Some capacitors in microelectronic devices include organic polymer material in the capacitor dielectric. In some cases, the organic polymer material provides substantially the complete capacitor dielectric. In other cases, the organic polymer material may be combined with inorganic dielectric material such as silicon dioxide to provide the capacitor dielectric. Organic polymer material typically provides better voltage surge performance than silicon dioxide. Microelectronic devices with capacitors including organic polymer material in the capacitor dielectric are commonly less expensive to fabricate then similar devices with inorganic dielectric material. Unfortunately, organic polymer material in the capacitor dielectric is subject to reliability problems, including reduced breakdown voltage over time, which is commonly estimated by a time dependent dielectric breakdown (TDDB) test. In a TDDB test of a capacitor, a constant stress voltage is applied to the capacitor until leakage current through the capacitor exceeds a specified limit, which is defined as breakdown of the capacitor dielectric. The length of time the stress voltage is applied until breakdown provides an estimate of reliability of the capacitor in a defined operating environment at a prescribed operating voltage.